NZ620265B2 - Leaf spring and compressor with leaf spring - Google Patents

Abstract

Reciprocating compressor provided with leaf springs 1 comprising at least one spacer 3 disposed between at least a pair of flat springs 2, each flat spring 2 being comprised by at least one outer ring 21, at least one inner ring 22 and at least one connection extension 23 capable of connecting an outer ring 21 to an inner ring 22. The outer ring 21 and the inner ring 22 are concentric to each other. The leaf springs comprise at least one section of physical contact between at least a pair of outer rings defined by at least one spacer, at least one section of physical contact between at least a pair of inner rings defined by at least one spacer, and at least one section free of physical contact between at least two connection extensions adjacently arranged. Each spacer 3 comprises an inner spacer which has analogous diameter to the diameter of the inner ring and an outer spacer which has analogous diameter to the diameter of the outer ring. ter ring 21 to an inner ring 22. The outer ring 21 and the inner ring 22 are concentric to each other. The leaf springs comprise at least one section of physical contact between at least a pair of outer rings defined by at least one spacer, at least one section of physical contact between at least a pair of inner rings defined by at least one spacer, and at least one section free of physical contact between at least two connection extensions adjacently arranged. Each spacer 3 comprises an inner spacer which has analogous diameter to the diameter of the inner ring and an outer spacer which has analogous diameter to the diameter of the outer ring.

Description

"RECIPROCATING COMPRESSOR PROVIDED WITH LEAF SPRINGS".

Field of the Invention The present invention relates to compressor leaf springs, in particular, linear com- pressor leaf springs, and a compressor provided with leaf springs, in particular, a linear com- pressor that is provided with at least two leaf springs cooperatively disposed at least one of the linear compressor mechanisms.

Background of the Invention As it is well known to those skilled in the art, a compressor comprises a mechanical (or electromechanical) device capable of raising the pressure of a particular working fluid, so that said working fluid, once "pressurized", can be used in different applications.

Among the types of compressor belonging to the current state of the art, it is known the reciprocating compressors. Such compressors are capable of raising the pressure of a working fluid by changing volume of a "chamber" where the mentioned working fluid is tem- porarily disposed. In this sense, reciprocating compressors uses a cylinder-piston assembly for promoting the volumetric change of the "chamber" where said working fluid is temporarily disposed, the inner portion of the cylinder defining itself such chamber, whose inner volume is changed as the piston is displaced, which moves axially within said cylinder. The piston movement is normally imposed by a driving source, which is normally defined by an electric motor.

In general, the type of electric motor to be used in a reciprocating compressor ends up defining the compressor nomenclature. In this regard, linear compressors are known which are based on linear electric motors (motor composed of a static stator and an axially dynamic cursor).

It is further known to those skilled in the art that linear compressors can also be based on resonant oscillatory mechanisms (resonant spring-mass assembly). A linear com- pressor based on resonant oscillating mechanisms, as defined in specialized literature and patent documents (for example, document BRPI 0601645-6) includes a linear motor and a piston, both functionally interconnected to each other through a resonant spring.

In this sense, the state of the art also provides working examples of linear compres- sor based on resonant oscillating mechanisms. One of those examples is described in a Bra- zilian document (BRPI1005184) No. 018100049527 (protocol number), of 12/27/2010. This document discloses a compressor comprising a resonant oscillating assembly (functional arrangement consisting of linear motor, resonant spring and piston) arranged within an in- termediate body (capable of providing axial flexibility to the resonant oscillating assembly).

Further according to this document, the resonant oscillating assembly is fastened to the in- termediate body by means of a fastening element. It was further noticed that the resonant oscillating assembly has its radial positioning (within the intermediate body) defined by at least one positioner element (flat spring) aligned with the said oscillating resonant assembly and the intermediate body. The positioner element (flat spring) as defined in this document comprises a body consisting of two rings (having different diameters) concentrically arranged and interconnected to each other by at least one connection extension. In this case, the “out- er” ring is fastened to the intermediate body and the ”inner” ring is fastened to the resonant spring.

Of course, this type of flat spring comprises is just an exemplification, that is, the present state of the art further provides other models and constructions of flat springs.

The current state of the art also provides flat leaf springs, which may or may not be used together or as substitution for flat springs and in similar applications (in order to ensure the radial positioning / alignment between a resonant oscillating assembly and an intermedi- ate body (or shell) of a linear compressor.

An example of a leaf spring (not necessarily used in linear compressors) is de- scribed in document US 3,786,834. This document provides a leaf spring comprised of flat springs and spacers arranged between the flat springs. In this case, the spacers comprise a shape that is basically analogous to the shape of flat springs, and have the function of transmitting movement from one spring to another, acting as a sort of physical connector therebetween.

Another example of beam spring (not necessarily used in linear compressors) is de- scribed in document US 5,415,587. This document provides a leaf spring also comprised of flexible disks and spacers arranged between the flexible disks. In this case, said spacers have only the function of attenuating vibration between flexible disks, and therefore, they are likely to present oscillatory movements relative to the flexible disks.

Yet another example of leaf spring is described in document US 3,462,136. This document reveals a leaf spring comprised of flat springs, said flat springs comprised by inner and outer rings and spokes arranged in such way that provide radial spacing between said inner and outer rings of the same flat spring.

Moreover, document DE-A-102005038783 discloses a linear compressor compris- ing a piston capable of being reciprocally displaced inside a cylinder, a linear motor acting on the piston and a resonance springs arrangement, wherein said resonance springs arrange- ment comprises a plurality of flat springs stacked to one another, each flat spring defined by a flat plate provided with a basically spiral slit, which allows said flat springs to displace its inner regions relatively to its outer regions. However, document DE-A-102005038783 does not reveal connection extensions free of physical contact due to spacers disposed between adjacently arranged flat springs.

The current state of the art also comprises different types of flat leaf springs; how- ever (and as well as the two examples recited above), most of those types of leaf springs is not able to replace the flat springs used in linear compressors. This impossibility is due main- ly to two reasons, namely: Such exemplifications of leaf springs are unable to ensure the radial rigidity that is necessary for the correct functioning of the resonant oscillatory assembly, that is, they are unable to ensure the radial positioning between resonant oscillating assembly and an inter- mediate body (or shell) of a linear compressor.

Such leaf springs have configurations that allow to integrally (or semi-integrally) con- tact resilient regions of a spring with the other resilient regions of other spring. Thus, those settings allow the flat springs, when in a state of maximum compression, to be capable of blocking (condition where the "links" of a spring (or a leaf springs) are physically contacted to each other, substantially changing the resilient characteristics of the assembly), this charac- teristic being highly undesirable in applications related to oscillatory movements, such as the linear compressors.

Therefore, the current state of the art does not provide leaf springs that may be used in linear compressors, in particular, in linear compressors based on resonant oscillatory mechanisms.

The reference to any prior art in the specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge in New Zealand.

Objects of the Invention Thus, it is one of the objects of the present invention to provide a leaf spring that may be applied in linear compressors based on resonant oscillatory mechanisms.

Therefore, it is another object of the present invention to provide a leaf spring capa- ble of ensuring the radial positioning of the resonant oscillatory assembly of a linear com- pressor relative to the shell (or intermediate body) thereof.

It is further another object of the present invention to provide a leaf spring whose spacers mechanically isolate resilient portions of two adjacently arranged flat springs (and, naturally, spaced from each other by one of those spacers).

It is also another object of this invention to disclose a leaf spring that may enable size reduction of a linear compressor, in particular, the overall diameter of the linear com- pressor.

It is an object of the invention to provide a leaf spring or reciprocating compressor provided with leaf springs apparatus and/or a method which overcomes or at least amelio- rates one or more disadvantages of the prior art, or alternatively to at least provide the public with a useful choice.

Summary of the Invention These and other objects of the invention disclosed herein are fully achieved by means of leaf springs for compressor disclosed herein.

Said compressor leaf springs comprises at least a spacer arranged between at least a pair of flat springs, each flat spring being comprised of at least one outer ring, at least one inner ring and at least one connection extension capable of connecting a an outer ring to an inner ring.

According to the present invention, the leaf springs reported herein comprises at least one inner section of physical contact between at least a pair of outer rings defined by at least one outer spacer, at least one section of physical contact between at least one pair of inner rings defined by at least one spacer and at least one section free of physical contact between at least two adjacently arranged connection extensions. Preferably, two adjacently arranged connection extensions are entirely free of physical contact with each other. Still preferably, the connection extensions of a pair of flat springs adjacently arranged are paral- lel, and a flat spring comprises, essentially, three connection extensions.

Further according to the present invention, the spacers comprise a body that is es- sentially annular. Moreover, each spacer is comprised by an inner spacer and an outer spacer, wherein the outer spacer has dimensions that are analogous to the dimensions of the outer ring of the flat spring, and the inner spacer has dimensions that are analogous to the dimensions of the inner ring of the flat spring.

The present invention also comprises a compressor provided with the flat leaf springs (recited above), which relates to a compressor preferably based on a resonant oscil- lating mechanism comprising at least two leaf springs arranged on at least one of distal ends of the shell. Preferably, it is provided at least one leaf spring arranged on each of the distal ends of the shell.

Optionally, it is provided a compressor provided with the flat leaf springs (recited above), which relates to a compressor preferably based on a resonant oscillating mechanism comprising at least two leaf springs arranged on at least one of distal ends of its intermediate body. Preferably, it is provided at least one leaf spring arranged on each of the distal ends of its intermediate body.

In a further aspect of the invention the invention may be said to broadly consist in a reciprocating compressor provided with leaf springs comprising at least one spacer disposed between at least a pair of flat springs, each flat spring being comprised by at least one outer ring, at least one inner ring, said at least one outer ring and said at least one inner ring being concentrically disposed in relation to each other, and at least one connection extension ca- pable of connecting the at least one outer ring to the at least one inner ring; wherein the leaf springs comprise: at least one section of physical contact between at least a pair of outer rings de- fined by at least one spacer; at least one section of physical contact between at least a pair of inner rings defined by at least one spacer; and at least one section free of physical contact between at least two connection ex- tensions adjacently arranged; wherein each spacer is comprised by an inner spacer which has analogous diame- ter to the diameter of the inner ring and an outer spacer which has analogous diameter to the diameter of the outer ring.

Brief Description of the Figures The present invention will be described in details based on the figures listed herein below, wherein: Figure 1 illustrates a flat spring (according to the invention), in a perspective view; Figure 2 illustrates the leaf springs (according to the invention), in a perspective view; Figure 3 illustrates the flat leaf springs (according to the invention), in a exploded view; Figure 4 illustrates a schematic cut view of flat leaf springs (according to the inven- tion); and Figure 5 illustrates, in schematic cut view, an example of a compressor provided with leaf springs (according to the invention).

Detailed Description of the Invention According to the concepts and objects of the present invention, the present inven- tion discloses a leaf springs 1 capable of incorporating a compressor - based on a resonant oscillating mechanism - mainly comprised of flat springs adjacently arranged and spaced from each other by spacers, each pair of flat spring providing a spacer between at least two springs that integrate the pair.

Also according to the present invention, each of the flat springs defines two support- ing regions and an axially resilient region, only the supporting regions of the flat springs be- ing "interconnected" to each other. Thus, axially resilient regions of a flat spring (when the same are associated with each other, conforming the leaf springs itself) will not exhibit any type of physical contact with axially resilient regions of other flat springs adjacently disposed.

This concept avoids that, at full load deformation, the leaf springs is subject to block- ing, since the axially resilient regions are free.

Figures 1, 2, 3 and 4 illustrate a preferred construction of the leaf springs 1.

According to those figures, it is ascertained that said leaf springs 1 comprises a second plurality of flat springs, which are spaced from each other by spacers 3.

Still according to this preferred construction, each flat spring 2 comprises an outer ring 21, an inner ring 22 and three connection extensions 23. In this context, both the outer ring 21 and the inner ring 22 comprise simplified annular bodies, which are interconnected by three extensions 23. Each of the extensions 23 - which are equidistantly arranged - compris- es a type of projection of an essentially semi-circular perimeter having arched distal ends.

Preferably, each of the flat springs 2 integrating the leaf spring 1 is made of a metal alloy.

This construction enables a single flat spring 2 to be capable of axial flexibility, that is, the rings 21 and 22 can move axially (relative to one another), this movement resulting from resilient deformation (in an axial direction) of the extension structures 23.

Also according to the preferable construction of the present invention, each of the spacers 3 comprises a simplified and essentially annular body. Spacers are provided in two different dimensions (perimeters). Therefore, it is provided outer spacers 3B having dimen- sions that are analogous to the dimensions of the outer ring 21 of the flat spring 2, and it is provided inner spacers 3A having dimensions that are analogous to the dimensions of the inner ring 22 of the flat spring 2. Also preferably, the spacers 3 are made of metal alloy.

Due to this construct, at least two flat springs 2 are interconnected to each other in parallel by means of two spacers 3.

Outer spacers 3B is arranged between two outer rings 21 of flat springs 2 arranged in parallel. Thus, this outer spacer 3B ends up defining the physical contact between (at least a section) of a pair of outer rings 21.

Inner spacer 3A is arranged between two inner rings 22 of flat springs 2 arranged in parallel. Thus, this inner spacer 3A ends up defining the physical contact between (at least a section) of a pair of inner rings 22.

Therefore, the spacers 3 end up defining contact sections or areas (between two parallel and / or adjacent flat springs 2) only where it is important to have contact sections or areas, since the connection extensions 23 of the flat springs 2 are free from each other, that is, the connection extensions 23 do not provide physical contact with the adjacent connection extensions 23, therefore avoiding any "blocking".

Preferably, the inner spacers 3A (located between the inner rings 22) are fastened by pressure between the flat springs 2, in particular during some assembling steps of the other elements integrating the linear compressor (during the process of inserting the ele- ments that will accomplish joining connecting–rod and magnet to the resonant spring).

Also preferably, the outer spacers 3B (located between the outer rings 21) are fas- tened by pressure between the flat springs 2, in particular during some steps of assembling the other elements integrating the linear compressor (when the resonant assembly is posi- tioned within the shell and the whole mechanism is pressed).

The present invention further comprises preferable constructs of linear compressors based on oscillating resonant mechanisms that are provided with leaf springs 1.

In general, a leaf spring 1- when properly associated with a compressor of this type - has as a main goal to keep the radial alignment of the resonant mechanism (resonant spring, linear motor, and cylinder-piston assembly) within the compressor shell, or, further, within an intermediate element (element described in the Brazilian document (BRPI1005184) (Previ- ously No. 018100049527 (protocol number), of 12/27/2010)).

According to the concepts of the present invention, the flat spring 2 of one of the dis- tal ends of the leaf spring 1 has its inner ring 22 physically coupled to one end of the reso- nant spring of the oscillating resonant assembly of the compressor. The outer ring 21 of this same flat spring 2 is physically coupled to one of the distal ends of the compressor shell, or further, to one of the distal ends of the intermediate element of the compressor (if applica- ble).

Preferably, another leaf springs 1 is also associated with the distal ends that are op- posing the compressor (of the resonant spring and the shell - or intermediate element -).

As the inner rings 22 are capable of axially moving relative to the outer rings 21, the leaf springs 1 allow the compressor resonant spring to "expand" and "shrink" without difficul- ty, while the compressor shell (or intermediate element) remains static.

Figure 5 illustrates an example of a linear compressor 4 provided with a leaf springs 1, which connect the ends of the resonant spring to the ends of the intermediate element 5.

Having described examples of embodiments of the subject matter of the present in- vention, it is clear that the scope thereof encompasses other possible variations (especially configurative variations of flat springs integrating the herein treated leaf springs), which are limited only by the content of the set of claims, being further included therein the possible equivalent means.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of “includ- ing, but not limited to”.

Claims (11)

1. Reciprocating compressor provided with leaf springs comprising at least one spacer disposed between at least a pair of flat springs, each flat spring being comprised by at least one outer ring, at least one inner ring, said at least one outer ring and said at least 5 one inner ring being concentrically disposed in relation to each other, and at least one con- nection extension capable of connecting the at least one outer ring to the at least one inner ring; wherein the leaf springs comprise: at least one section of physical contact between at least a pair of outer rings de- fined by at least one spacer; 10 at least one section of physical contact between at least a pair of inner rings defined by at least one spacer; and at least one section free of physical contact between at least two connection ex- tensions adjacently arranged; wherein each spacer is comprised by an inner spacer which has analogous diame- 15 ter to the diameter of the inner ring and an outer spacer which has analogous diameter to the diameter of the outer ring.

2. Reciprocating compressor, according to claim 1, wherein the two connection ex- tensions adjacently arranged are fully free of physical contact between each other.

3. Reciprocating compressor, according to claim 1, wherein the inner and outer 20 spacers comprise essentially annular bodies.

4. Reciprocating compressor, according to claim 1, wherein the connection exten- sions of at least one pair of flat springs adjacently arranged are parallel.

5. Reciprocating compressor, according to claim 1, wherein the flat spring essential- ly comprise three connection extensions. 25

6. Reciprocating compressor, according to any one of claims 1 to 5, wherein the re- ciprocating compressor is based on a resonant oscillating mechanism;

7. Reciprocating compressor, according to claim 6, comprising the leaf springs ar- ranged on at least one distal end of a compressor.

8. Reciprocating compressor, according to claim 7, comprising the leaf springs ar- 30 ranged at each one of distal ends of the compressor.

9. Reciprocating compressor, according to any one of claims 1 to 8, comprising the leaf springs arranged on at least one distal end of an intermediate body of the compressor.

10. Reciprocating compressor, according to claim 7, comprising the leaf springs ar- ranged at each one of distal ends of the intermediate body of the compressor. 35

11. A Reciprocating compressor substantially as herein described with reference to any one or more the accompanying drawings.